Multifunctional materials are materials which undergo a deformation or exert deformation forces if the deformation is prevented as a reaction to a physical parameter which can be externally altered. Examples of multifunctional materials are piezoceramics, piezopolymers, electrostrictive ceramics and electrorheological liquids, where the required deformation is achieved through the application of an electric field, magnetostrictive alloys and magnetorheological liquids, where the required deformation is achieved through the application of a magnetic field, as well as shape memory alloys, shape memory polymers and hybrid material systems, where the desired deformation is achieved through a change in temperature.
The arbitrary deformation of multifunctional materials is exploited in the design of actuators. The most common example are those piezoceramics directly used as actuators. The disadvantage here is the short regulating distance of all actuators in which the deformation of the multifunctional material is directly exploited.
It is thus necessary to provide a displacement transmission for the deformation of the multifunctional material if large regulating distances have to be implemented. Known displacement transmissions include mechanical and hydraulic levers, though these contain a number of moving parts and thus display a high weight and great susceptibility to faults.